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{
"metadata": {
"name": "chapter-21.ipynb"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h1>Chapter 21: More Linux Programming <h1>"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>SIGINT Example , Page number: 669<h3>"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''Program to prevent the termination of a program even after hitting Ctrl + C'''\n",
"\n",
"import signal, os\n",
"\n",
"def sighandler ( signum,arg ):\n",
" print ( \"SIGINT received. Inside sighandler\" ) \n",
"\n",
"\n",
"signal.signal(signal.SIGINT,sighandler)\n",
"while ( 1 ):\n",
" print \"Program Running\" \n"
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>Handling Multiple Signals , Page number: 671<h3>"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''Program to handle multiple signals.'''\n",
"\n",
"import signal, os\n",
"\n",
"def inthandler ( signum,arg ):\n",
" print \"SIGINT Received\" \n",
" \n",
"def termhandler ( signum ,arg):\n",
" print \"SIGTERM Received\" \n",
" \n",
"def conthandler ( signum,arg ):\n",
" print \"SIGCONT Received\" \n",
" \n",
"\n",
"signal.signal(signal.SIGINT,inthandler)\n",
"signal.signal(signal.SIGTERM,termhandler)\n",
"signal.signal(signal.SIGCONT,conthandler)\n",
"\n",
"while ( 1 ):\n",
" print \"Program Running\" "
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>Registering A Common Handler , Page number: 673<h3>"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''Program to demonstrate a common signal handler to handle all signals\n",
"instead of registering a separate handler for each signal'''\n",
"\n",
"import signal, os\n",
"\n",
"def sighandler ( signum ,arg):\n",
" if(signum == SIGINT):\n",
" print \"SIGINT Received\" \n",
" elif(signum == SIGTERM):\n",
" print \"SIGTERM Received\" \n",
" elif(signum == SIGCONT):\n",
" print \"SIGCONT Received\" \n",
"\n",
"signal.signal(signal.SIGINT,sighandler)\n",
"signal.signal(signal.SIGTERM,sighandler)\n",
"signal.signal(signal.SIGCONT,sighandler)\n",
"\n",
"while ( 1 ):\n",
" print \"Program running\" \n"
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>Blocking Signals , Page number: 675<h3>"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''Program to understand signal blocking '''\n",
"\n",
"import signal, os\n",
"\n",
"def sighandler ( signum ,arg):\n",
" if(signum == SIGINT):\n",
" print (\"SIGINT Received\") \n",
" elif(signum == SIGTERM):\n",
" print (\"SIGTERM Received\" )\n",
" elif(signum == SIGCONT):\n",
" print ( \"SIGCONT Received\" )\n",
"\n",
"buffer = \"\\0\"\n",
"signal.signal(signal.SIGINT,sighandler)\n",
"signal.signal(signal.SIGTERM,sighandler)\n",
"signal.signal(signal.SIGCONT,sighandler)\n",
"\n",
"signal.pthread_sigmask(signal.SIG_BLOCK, [])\n",
"\n",
"while ( buffer == \"\\0\" ):\n",
" buffer = input(\"Enter a string\")\n",
" print (buffer)\n",
"signal.pthread_sigmask(signal.SIG_UNBLOCK, [])\n",
"while(1):\n",
" print(\"Program running\")\n"
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>Event Driven Programming , Page number: 678<h3>"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''Program that uses GTK toolkit to create a window on the screen.'''\n",
"\n",
"from tkinter import *\n",
"\n",
"\n",
"class Example(Frame):\n",
" def __init__(self, parent):\n",
" Frame.__init__(self, parent)\n",
"\n",
" self.display = Canvas(self, width=700, height=200)\n",
" self.display.pack(side=\"top\", fill=\"both\", expand=True)\n",
" \n",
"if __name__ == \"__main__\":\n",
" root = Tk()\n",
" root.title(\"Sample Window\")\n",
" Frame = Example(parent=root)\n",
" Frame.pack(side=\"top\", fill=\"both\", expand=True)\n",
" root.mainloop()"
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>MyShapes , Page number: 681<h3>"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"'''Program to draw a few shapes in a window'''\n",
"\n",
"from tkinter import *\n",
"\n",
"\n",
"top = Tk()\n",
"top.title(\"Sample Window\")\n",
"C = Canvas(top, height=500, width=500)\n",
"rcoor = 10,20,200,100\n",
"rect = C.create_rectangle(rcoor,fill=\"black\")#rectangle\n",
"picoor = 250,0,350,100\n",
"pie = C.create_arc(picoor, start=300, extent=100, fill=\"black\")#pie\n",
"pocoor = 250, 150, 250, 300, 300, 350, 400, 300, 320, 190\n",
"polygon = C.create_polygon(pocoor,fill=\"black\")#polygon\n",
"C.pack()\n",
"top.mainloop()\n"
],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}
|
